13811476781 has 2 divisors, whose sum is σ = 13811476782. Its totient is φ = 13811476780.

The previous prime is 13811476771. The next prime is 13811476799. The reversal of 13811476781 is 18767411831.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8679903556 + 5131573225 = 93166^2 + 71635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13811476781 is a prime.

It is a super-2 number, since 2×13811476781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13811476741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6905738390 + 6905738391.

It is an arithmetic number, because the mean of its divisors is an integer number (6905738391).

Almost surely, 2^13811476781 is an apocalyptic number.

It is an amenable number.

13811476781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13811476781 is an equidigital number, since it uses as much as digits as its factorization.

13811476781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225792, while the sum is 47.

The spelling of 13811476781 in words is "thirteen billion, eight hundred eleven million, four hundred seventy-six thousand, seven hundred eighty-one".